Miniaturized cross-point

ABSTRACT

In this integrated and miniaturized crosspoint packed in a sealed casing which forms a magnetic shielding, each reed is surrounded by a coil, and is tailed in a base while its end carries the contact. Two such reeds are respectively inserted in two coils or coil assemblies located side by side, to form a contact arrangement. Each reed is made of two half-reeds forming a closed V, one branch of the V being made of resilient material and having its top end secured to the base, while the other branch is made of magnetic remanent material and carries the contact material located at its top end.

United States Patent 1 Raso et al.

[45] Apr. 30, 1974 MINIATURIZED CROSS-POINT [75] Inventors: Jean Baptiste Raso, Paris;

Emmanuel Marie-Augustin Jammes, Boulogne, both of France [73] Assignee: International Standard Electric Corporation, New York, NY.

22 Filed: Jan. 30, 1973 21 Appl. No.: 327,887

' "rdrignp raafiah mam ma Jail. 3119 7 5 Fiat 66; .IQI72Q03105 [52 1 Us. Ci;.;..Li....IIiI..;.;..;II.I..T3/is3, 335/112 [51] int. Cl. ..H0lh 51/27 [58] Field of Search. 335/112, 151, 152, 153, 335/154 [56] References Cited UNITED STATES PATENTS 3/1970 Wasserman 335/153 UX 5/1970 Takamura et a1 335/153 A I60 I619 I061 3,587,011 6/1971 Kurz 335/151 Primary ExaminerRoy N. Envall, Jr. Attorney, Agent, or Firm-John T. OHalloran; Menotti J. Lombardi, Jr.

[ ABSTRACT In this integrated and miniaturized crosspoint packed in a sealed casing which forms a magnetic shielding, each reed is surrounded by a coil, and is tailed in a base while its end carries the contact. Two such reeds are respectively inserted in two coils or coil assemblies located side by side, to form a contact arrangement. Each reed is made of two half-reeds forming a closed V, one branch of the V being made of resilient material and having its top end secured to the base, while the other branch is made of magnetic remanent material and carries the contact material located at its top end.

4 Claims, 4 Drawing Figures MINIATURIZED CROSS-POINT The present invention relates to miniaturized electromagnetic sealed relays and, more particularly, to those relays which are used as crosspoints in switching matrices.

Such crosspoints and such matrices are well known and are, for example, described in the article Un autocommutateur te'lphonique e'lectronique (An electronic telephone exchange) by A. .l. I-Ienquet, issued in the No. 208 of the review Me'canique et Electricite' of March 1967.

In a known manner, it is of particular interest to reduce telephone exchange size, even only for making easier the solution of transmission between separate items and for reducing the consumption of energy converted in vain into heat, which results in component size reduction and, in particula'ncrosspoint size reduction.

In a conventional manner, reed-type crosspoints as described in the French Pat. of Addition No. 85,512 to the main French Pat. No. 1,393,336 filed by the applicant, have their coils located outside the bulbs including the contacts, which results in a small magnetic efficiency at the level of the crosspoints.

Moreover, important space intervals must be provided between adjacent crosspoints or additional shields must be provided for avoiding undesired mutual influences, such shields contributing to reduce magnetic efficiency of the assembly.

Still in a conventional manner, matrix crosspoint mounting is a complex operation if compared with mounting of other single components since coils and contacts are not associated before the matrix mount- To overcome those drawbacks and to permit a further miniaturization, it is provided according to the present invention a miniaturized bistable electromagnetic relay which is sealed in a magnetic-shielded sealed casing to form, in particular, crosspoint for switching matrices such as those used in the telephone field.

According to a feature of this invention, that relay comprises two coil assemblies located side by side inside the sealed casing, each coil assembly comprising one or several coaxial coils.

Thatielay' E6 compn sesjinside rhaeagih ffiw contact reeds m being an integer each being formed, on the one hand, with a resilient half-reed made of non-magnetic conducting material and'rigidly secured by one of its ends, and, on the other hand, with a half-reed made of remanent magnetic conducting material and provided with an electric contact area at one end while its other end is secured to the free end of the resilient half-reed in such a manner that those two halfreea se joiri'dside"by s'iiie,$59531? rearsberngiaa gitudinally arranged side by side per group of m" reeds inserted in the central recess of one of the two coil assemblies so that each reed may move in the recess, where it is inserted, for possibly contacting the corresponding reed inserted in the recess of the other coil assembly, when influenced byielectromagnetic fields produced by those coil assemblies.

Other features of this invention will appear more clearly from the following description of an embodiment, the said description being made in conjunction with the accompanying drawings, wherein:

FIG. 1 is a diagram of principle for defining the operation principle of a relay according to this invention,

FIG. 2 is a diagram of principle of a relay according to this invention arranged to constitute a matrix crosspoint, and

FIGS. 3a and 3b are cross-sectional views of an em bodiment according to this invention.

The relay, as shown in FIG. 1, comprises two contact reeds 1 and 2, made of resilient magnetic material and tailed in an insulating support 3 in such a manner that their contact ends 4 and 5 are only separated by a small space interval forming a magnetic gap.

Two empty coils 6 and 7 are respectively arranged, one around reed l and the other around reed 3, on the same side of support 3 as ends 4 and 5 Each central coil recess is so provided that the contact reed within it can move so as to contact the other reed.

When coils 6 and 7 are correctly supplied, contact ends 4 and 5 are magnetically attracted one toward the other and they establish an electric connection between reeds 1 and 2. If reeds l and 2 are made of remanent material, the contact remains established after having suppressed the supply current through the coils and it will only released by applying to the coils currents producing opposite inductions of sufficient values in reeds l and 2, so that the reeds move aside under combined actions of magnetic repulsion forces and of resilient forces. However, such an embodiment is difficult to operate because contact reeds must have conflicting characteristics.

Indeed, the forces which apply ends 4 and 5 one to the other are equal to the difference between magnetic attraction forces and resilient forces.

Magnetic attraction forces must be substantially higher than resilient forces to ensure a firm holding of contact closure after vanishing of control pulses. That needs the use of reeds having relatively important cross-section areas.

Resilient forces must be relatively small since, on the one hand, opening of contact formed by ends 4 and 5 is mainly due to magnetic repulsion effects and, on the other hand, such resilient forces are opposed to the magnetic attraction forces when contact is closing or closed. That needs the use of reeds having small crosssection areas with respect to the above mentioned cross-sectionarea.

However, it is to be noted that resilient forces must not be negligible for returning or maintaining thereeds at rest since repulsion forces from one reed to the other are reduced with the space interval between the reeds.

That problem is solved by using reeds having two portions as shown in FIG. 2, such two-portion reeds being suitable for a cross-point controlled by current pulses and being'provided with magnetic latching. The cross-point, as shown in FIG. 2, may comprise m pairs of reeds, only one being shown.

, As previously, reeds l and 2 are tailed in insulating support 3 mounted on a planar base 26 and are surrounded by empty coils 6 and 8 for reed l and coils 7 and 9 for reed 2. Each contact reed, such as 1, comprises:

a smaJl-cross-section half-reed 10 made of nonmagnetic conducting material acting as a spring and which is tailed in insulating support 3 and passes longitudinally through coils 6 and 8,

--a large-cross-section half-reed 12 made of remanent magnetic material and provided with an end contact 4, and which is secured to half-reed 10 at the end opposite to 4 so as to ensure electric continuity through the whole reed 1. v

Contact end 4 is located outside coils 6 and 8 whose holesare aligned and allow reed 1 to move for contacting end 5 of reed 2 with its end 4.

The operation of -a relay whose contact reeds are made in accordance with the above description is substantially identical to the operation briefly described in conjunction with FIG. 1 and needs no further explanations. Reversely, FIG. 2 permits to define the operation of cross-points, according to this invention, arranged in a rectangular matrix having n rows and p columns and coordinate controlled according to the method described, in particular, in the French Pat. No. 1,393,336 filed by the applicant.

In a known manner, the closure of the contact formed with reeds 1 and 2 is produced by simultaneously applying four pulses having selected current intensity and various durations on each of the four coils 6, 7, 8 and 9. The first pulse X is applied to cross-point coil 6 and to all corresponding coils in the n other cross-points not shown of the same row X.

The second pulse Y having a same duration as X, is applied to the cross-point coil 7 and to all the corresponding coils in the p cross-points of the same column Y in the matrix.

The two other pulses X, and Y are'shorter and are simultaneously applied with the first ones, X to coil 8 and to all the corresponding coils in the n crosspoints of row X such as previously mentioned in relation with pulse X and Y, to coil 9 and to all the corresponding coils in the'fp cross-points of column Y as previously mentioned in relation with Y In a conventional manner, when the four pulses X Y X and Y are simultaneously supplied to coils 6, 7, 8 and 9, reed l is subject to two flux which are equal and of opposite direction as produced by coils 6 and 8 while reed 2 is subject to two flux which also are equal and of opposite direction as produced by coils 8 and 9. As a result, those flux have no effect on the selected cross-point. Reversely, after vanishing of shorter pulses X and Y flux produced by coil 6 and flux produced by coil 7 magnetize in series remanant half-reeds l2 and 13. Ends 4 and 5 are contacting taking into account that fiux tend to reduce length of paths through which they are established so as to reduce the reluctance of the magnetic circuit they follow.

Pulses X and Y, having been suppressed, contact is held closed due to series remanent magnetizations of half-reeds 12 and 13.

Still in a conventional manner, if a cross-point is activated and if it belongs either to the same row or to the same column as the selected cross-point, say row X, it receives two pulses X and X: which produce flux of opposite directions in reeds l2 and 13 whose ends 4 and 5 are repelled by magnetic repulsion efiect pulse resilient effect of reeds l and 1 l, resilient forces relatively increasing when space interval between ends 4 and is increasing.

If ends 4 and 5 were already apart, flux produced by coils 6 and 9 are opposite directions and do not modify the contact rest condition.

In conjunction with that has been previously described, FIGS. 3a and 3b permit to define a cross-point of a miniaturized type made in tight casing forming a shield.

That cross-point comprises four coils 6, 7, 8 and 9 which are coaxial two by two and may be manufactured according to any means known to those skilled in the art. It comprises two pairs of contact reeds forming two separate contacts which are located side by side. Each group of coaxial coils, on the one hand, 6, 8 and, on the other hand, 7, 9 contains one reed of each contact in its central hole. The two reeds located in a same hole are each made of two half-reeds such as described in conjunction with FIG, 2. Thus coils 6 and 8 contain the two reeds comprising components 10a, 10b, 12a and 12b whichcan move inside their hole in such a manner that contact ends 4a and 4b can contact their corresponding contact ends 5a and 5b of reeds located in the hole of coils 7 and 9.

In the embodiment shown in FIGS. 3a and 3b, magnetic half-reeds, such as 12a, are composed of a single element with the corresponding end contact, such as 4a. For half-reed 12a, end contact 40 is, for instance, made of a metal coating deposited on a nonremanent magnetic area of reed 12a which is itself remanent magnetic out of that area, the contact area 4a being made, in a known manner, by distorting half-reed 12a.

Obviously, any other technique for manufacturing the contacts may be used for that purpose and, for example, the ultilization of added contacts as shown in FIG. 2.

FIGS. 3a and 312 also show a cap 14 made of nonremanent magnetic material, such as soft iron, which provides with the base 26,,on the one hand, a tight package and, on the other hand, a magnetic shielding.

Packing is made, for example, under neutral atmosphere for avoiding any further oxidation of contacts.

The magnetic shield makes it possible to arrange the various cross-points closer in a matrix without being afraid of mutual interference inductions which usually limits matrix size reduction.

Coil terminals such as 17, 18, 19, 20, 20, 21, 22, 23 and contact reeds 15a, 16a and 15b, 16b are arranged in two lines parallel to the length of base26 so as to make easy insertion on printed circuit boards, such a mounting being known as dual in line arrangement.

Insulation of terminals from base 26 is provided, for

example, by insulating and tight pinch lead imple-.

mented in a conventional manner.

In the selected embodiment, resilient half-reeds are made in non-magnetic material so as to avoid magnetic leakage toward the casing taking into account the closeness of those half-reeds and the casing in front of the terminals to which they are connected, such as 16aand 16b in front of half-reeds 10a and 10b.

. Reversely, resilient half-reed end, which is secured to I the magnetic half-reed, is located close to the adjacent casing wall so as to reduce the so produced magnetic gap reluctance up to a value determined by electric insulation needed between the considered conducting reed and the casing.

While the principles of the present invention have been hereabove described in relation with a specific embodiment, it will be clearly understood that the said description has only been made by way of example and does not limit the scope of this invention.

sembly are moved into contact with said reeds of said second coil assemblywhen electromagnetic fields are selectively produced by said coils containing said reeds.

2. The miniaturized crosspoint relay according to claim 1 wherein said casing consists of a non-remanent magnetic material.

3. The miniaturized crosspoint relay of claim 1 wherein said casing futther comprises:

a. a base; and

b. a plurality of electric terminals protruding through What is claimed is:

1. A miniaturized sealed bistable electromechanical crosspoint relay for use in switching matrices comprising:

a. a casing; 5

b. two coil assemblies consisting of first and second coil assemblies mounted side by side within said casing, each of said first and second coil assemblies containing a plurality of co-axial electromagnetic hollow core coils; and 10 c. a plurality of reeds inserted within the cores of said electromagnetic coils with one of said reeds corresponding to each said coil, each of said reeds including a pair of first and second laterally adjacent first arm including a resilient non-magnetic consaid base at least one said terminal connected to one said corresponding coil, and at least one said terminal connected to one said corresponding reed, said terminals being parallely arranged on said base to form a dual in-line pattern.

ducting material fixedly attached to said casing, 4. The miniaturized crosspoint relay of claim 1 said second arm including a remanent magnetic wherein each said coil assembly comprises two coaxial conducting material with an electric contact area hollow core coils. at one end, whereby said reeds of said first coil as- 

1. A miniaturized sealed bistable electromechanical crosspoint relay for use in switching matrices comprising: a. a casing; b. two coil assemblies consisting of first and second coil assemblies mounted side by side within said casing, each of said first and second coil assemblies containing a plurality of co-axial electromagnetic hollow core coils; and c. a plurality of reeds inserted within the cores of said electromagnetic coils with one of said reeds corresponding to each said coil, each of said reeds including a pair of first and second laterally adjacent contact arms connected together at one end, said first arm including a resilient non-magnetic conducting material fixedly attached to said casing, said second arm including a remanent magnetic conducting material with an electric contact area at one end, whereby said reeds of said first coil assembly are moved into contact with said reeds of said second coil assembly when electromagnetic fields are selectively produced by said coils containing said reeds.
 2. The miniaturized crosspoint relay according to claim 1 wherein said casing consists of a non-remanent maGnetic material.
 3. The miniaturized crosspoint relay of claim 1 wherein said casing futther comprises: a. a base; and b. a plurality of electric terminals protruding through said base at least one said terminal connected to one said corresponding coil, and at least one said terminal connected to one said corresponding reed, said terminals being parallely arranged on said base to form a dual in-line pattern.
 4. The miniaturized crosspoint relay of claim 1 wherein each said coil assembly comprises two coaxial hollow core coils. 